tools/perf/util/thread_map.c

   1 #include <dirent.h>
   2 #include <errno.h>
   3 #include <limits.h>
   4 #include <stdbool.h>
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9 #include <unistd.h>
  10 #include "string2.h"
  11 #include "strlist.h"
  12 #include <string.h>
  13 #include <api/fs/fs.h>
  14 #include "asm/bug.h"
  15 #include "thread_map.h"
  16 #include "util.h"
  17 #include "debug.h"
  18 #include "event.h"
  19
  20 /* Skip "." and ".." directories */
  21 static int filter(const struct dirent *dir)
  22 {
  23         if (dir->d_name[0] == '.')
  24                 return 0;
  25         else
  26                 return 1;
  27 }
  28
  29 static void thread_map__reset(struct thread_map *map, int start, int nr)
  30 {
  31         size_t size = (nr - start) * sizeof(map->map[0]);
  32
  33         memset(&map->map[start], 0, size);
  34 }
  35
  36 static struct thread_map *thread_map__realloc(struct thread_map *map, int nr)
  37 {
  38         size_t size = sizeof(*map) + sizeof(map->map[0]) * nr;
  39         int start = map ? map->nr : 0;
  40
  41         map = realloc(map, size);
  42         /*
  43          * We only realloc to add more items, let's reset new items.
  44          */
  45         if (map)
  46                 thread_map__reset(map, start, nr);
  47
  48         return map;
  49 }
  50
  51 #define thread_map__alloc(__nr) thread_map__realloc(NULL, __nr)
  52
  53 struct thread_map *thread_map__new_by_pid(pid_t pid)
  54 {
  55         struct thread_map *threads;
  56         char name[256];
  57         int items;
  58         struct dirent **namelist = NULL;
  59         int i;
  60
  61         sprintf(name, "/proc/%d/task", pid);
  62         items = scandir(name, &namelist, filter, NULL);
  63         if (items <= 0)
  64                 return NULL;
  65
  66         threads = thread_map__alloc(items);
  67         if (threads != NULL) {
  68                 for (i = 0; i < items; i++)
  69                         thread_map__set_pid(threads, i, atoi(namelist[i]->d_name));
  70                 threads->nr = items;
  71                 refcount_set(&threads->refcnt, 1);
  72         }
  73
  74         for (i=0; i<items; i++)
  75                 zfree(&namelist[i]);
  76         free(namelist);
  77
  78         return threads;
  79 }
  80
  81 struct thread_map *thread_map__new_by_tid(pid_t tid)
  82 {
  83         struct thread_map *threads = thread_map__alloc(1);
  84
  85         if (threads != NULL) {
  86                 thread_map__set_pid(threads, 0, tid);
  87                 threads->nr = 1;
  88                 refcount_set(&threads->refcnt, 1);
  89         }
  90
  91         return threads;
  92 }
  93
  94 struct thread_map *thread_map__new_by_uid(uid_t uid)
  95 {
  96         DIR *proc;
  97         int max_threads = 32, items, i;
  98         char path[NAME_MAX + 1 + 6];
  99         struct dirent *dirent, **namelist = NULL;
 100         struct thread_map *threads = thread_map__alloc(max_threads);
 101
 102         if (threads == NULL)
 103                 goto out;
 104
 105         proc = opendir("/proc");
 106         if (proc == NULL)
 107                 goto out_free_threads;
 108
 109         threads->nr = 0;
 110         refcount_set(&threads->refcnt, 1);
 111
 112         while ((dirent = readdir(proc)) != NULL) {
 113                 char *end;
 114                 bool grow = false;
 115                 struct stat st;
 116                 pid_t pid = strtol(dirent->d_name, &end, 10);
 117
 118                 if (*end) /* only interested in proper numerical dirents */
 119                         continue;
 120
 121                 snprintf(path, sizeof(path), "/proc/%s", dirent->d_name);
 122
 123                 if (stat(path, &st) != 0)
 124                         continue;
 125
 126                 if (st.st_uid != uid)
 127                         continue;
 128
 129                 snprintf(path, sizeof(path), "/proc/%d/task", pid);
 130                 items = scandir(path, &namelist, filter, NULL);
 131                 if (items <= 0)
 132                         goto out_free_closedir;
 133
 134                 while (threads->nr + items >= max_threads) {
 135                         max_threads *= 2;
 136                         grow = true;
 137                 }
 138
 139                 if (grow) {
 140                         struct thread_map *tmp;
 141
 142                         tmp = thread_map__realloc(threads, max_threads);
 143                         if (tmp == NULL)
 144                                 goto out_free_namelist;
 145
 146                         threads = tmp;
 147                 }
 148
 149                 for (i = 0; i < items; i++) {
 150                         thread_map__set_pid(threads, threads->nr + i,
 151                                             atoi(namelist[i]->d_name));
 152                 }
 153
 154                 for (i = 0; i < items; i++)
 155                         zfree(&namelist[i]);
 156                 free(namelist);
 157
 158                 threads->nr += items;
 159         }
 160
 161 out_closedir:
 162         closedir(proc);
 163 out:
 164         return threads;
 165
 166 out_free_threads:
 167         free(threads);
 168         return NULL;
 169
 170 out_free_namelist:
 171         for (i = 0; i < items; i++)
 172                 zfree(&namelist[i]);
 173         free(namelist);
 174
 175 out_free_closedir:
 176         zfree(&threads);
 177         goto out_closedir;
 178 }
 179
 180 struct thread_map *thread_map__new(pid_t pid, pid_t tid, uid_t uid)
 181 {
 182         if (pid != -1)
 183                 return thread_map__new_by_pid(pid);
 184
 185         if (tid == -1 && uid != UINT_MAX)
 186                 return thread_map__new_by_uid(uid);
 187
 188         return thread_map__new_by_tid(tid);
 189 }
 190
 191 static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)
 192 {
 193         struct thread_map *threads = NULL, *nt;
 194         char name[256];
 195         int items, total_tasks = 0;
 196         struct dirent **namelist = NULL;
 197         int i, j = 0;
 198         pid_t pid, prev_pid = INT_MAX;
 199         char *end_ptr;
 200         struct str_node *pos;
 201         struct strlist_config slist_config = { .dont_dupstr = true, };
 202         struct strlist *slist = strlist__new(pid_str, &slist_config);
 203
 204         if (!slist)
 205                 return NULL;
 206
 207         strlist__for_each_entry(pos, slist) {
 208                 pid = strtol(pos->s, &end_ptr, 10);
 209
 210                 if (pid == INT_MIN || pid == INT_MAX ||
 211                     (*end_ptr != '\0' && *end_ptr != ','))
 212                         goto out_free_threads;
 213
 214                 if (pid == prev_pid)
 215                         continue;
 216
 217                 sprintf(name, "/proc/%d/task", pid);
 218                 items = scandir(name, &namelist, filter, NULL);
 219                 if (items <= 0)
 220                         goto out_free_threads;
 221
 222                 total_tasks += items;
 223                 nt = thread_map__realloc(threads, total_tasks);
 224                 if (nt == NULL)
 225                         goto out_free_namelist;
 226
 227                 threads = nt;
 228
 229                 for (i = 0; i < items; i++) {
 230                         thread_map__set_pid(threads, j++, atoi(namelist[i]->d_name));
 231                         zfree(&namelist[i]);
 232                 }
 233                 threads->nr = total_tasks;
 234                 free(namelist);
 235         }
 236
 237 out:
 238         strlist__delete(slist);
 239         if (threads)
 240                 refcount_set(&threads->refcnt, 1);
 241         return threads;
 242
 243 out_free_namelist:
 244         for (i = 0; i < items; i++)
 245                 zfree(&namelist[i]);
 246         free(namelist);
 247
 248 out_free_threads:
 249         zfree(&threads);
 250         goto out;
 251 }
 252
 253 struct thread_map *thread_map__new_dummy(void)
 254 {
 255         struct thread_map *threads = thread_map__alloc(1);
 256
 257         if (threads != NULL) {
 258                 thread_map__set_pid(threads, 0, -1);
 259                 threads->nr = 1;
 260                 refcount_set(&threads->refcnt, 1);
 261         }
 262         return threads;
 263 }
 264
 265 struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
 266 {
 267         struct thread_map *threads = NULL, *nt;
 268         int ntasks = 0;
 269         pid_t tid, prev_tid = INT_MAX;
 270         char *end_ptr;
 271         struct str_node *pos;
 272         struct strlist_config slist_config = { .dont_dupstr = true, };
 273         struct strlist *slist;
 274
 275         /* perf-stat expects threads to be generated even if tid not given */
 276         if (!tid_str)
 277                 return thread_map__new_dummy();
 278
 279         slist = strlist__new(tid_str, &slist_config);
 280         if (!slist)
 281                 return NULL;
 282
 283         strlist__for_each_entry(pos, slist) {
 284                 tid = strtol(pos->s, &end_ptr, 10);
 285
 286                 if (tid == INT_MIN || tid == INT_MAX ||
 287                     (*end_ptr != '\0' && *end_ptr != ','))
 288                         goto out_free_threads;
 289
 290                 if (tid == prev_tid)
 291                         continue;
 292
 293                 ntasks++;
 294                 nt = thread_map__realloc(threads, ntasks);
 295
 296                 if (nt == NULL)
 297                         goto out_free_threads;
 298
 299                 threads = nt;
 300                 thread_map__set_pid(threads, ntasks - 1, tid);
 301                 threads->nr = ntasks;
 302         }
 303 out:
 304         if (threads)
 305                 refcount_set(&threads->refcnt, 1);
 306         return threads;
 307
 308 out_free_threads:
 309         zfree(&threads);
 310         strlist__delete(slist);
 311         goto out;
 312 }
 313
 314 struct thread_map *thread_map__new_str(const char *pid, const char *tid,
 315                                        uid_t uid)
 316 {
 317         if (pid)
 318                 return thread_map__new_by_pid_str(pid);
 319
 320         if (!tid && uid != UINT_MAX)
 321                 return thread_map__new_by_uid(uid);
 322
 323         return thread_map__new_by_tid_str(tid);
 324 }
 325
 326 static void thread_map__delete(struct thread_map *threads)
 327 {
 328         if (threads) {
 329                 int i;
 330
 331                 WARN_ONCE(refcount_read(&threads->refcnt) != 0,
 332                           "thread map refcnt unbalanced\n");
 333                 for (i = 0; i < threads->nr; i++)
 334                         free(thread_map__comm(threads, i));
 335                 free(threads);
 336         }
 337 }
 338
 339 struct thread_map *thread_map__get(struct thread_map *map)
 340 {
 341         if (map)
 342                 refcount_inc(&map->refcnt);
 343         return map;
 344 }
 345
 346 void thread_map__put(struct thread_map *map)
 347 {
 348         if (map && refcount_dec_and_test(&map->refcnt))
 349                 thread_map__delete(map);
 350 }
 351
 352 size_t thread_map__fprintf(struct thread_map *threads, FILE *fp)
 353 {
 354         int i;
 355         size_t printed = fprintf(fp, "%d thread%s: ",
 356                                  threads->nr, threads->nr > 1 ? "s" : "");
 357         for (i = 0; i < threads->nr; ++i)
 358                 printed += fprintf(fp, "%s%d", i ? ", " : "", thread_map__pid(threads, i));
 359
 360         return printed + fprintf(fp, "\n");
 361 }
 362
 363 static int get_comm(char **comm, pid_t pid)
 364 {
 365         char *path;
 366         size_t size;
 367         int err;
 368
 369         if (asprintf(&path, "%s/%d/comm", procfs__mountpoint(), pid) == -1)
 370                 return -ENOMEM;
 371
 372         err = filename__read_str(path, comm, &size);
 373         if (!err) {
 374                 /*
 375                  * We're reading 16 bytes, while filename__read_str
 376                  * allocates data per BUFSIZ bytes, so we can safely
 377                  * mark the end of the string.
 378                  */
 379                 (*comm)[size] = 0;
 380                 rtrim(*comm);
 381         }
 382
 383         free(path);
 384         return err;
 385 }
 386
 387 static void comm_init(struct thread_map *map, int i)
 388 {
 389         pid_t pid = thread_map__pid(map, i);
 390         char *comm = NULL;
 391
 392         /* dummy pid comm initialization */
 393         if (pid == -1) {
 394                 map->map[i].comm = strdup("dummy");
 395                 return;
 396         }
 397
 398         /*
 399          * The comm name is like extra bonus ;-),
 400          * so just warn if we fail for any reason.
 401          */
 402         if (get_comm(&comm, pid))
 403                 pr_warning("Couldn't resolve comm name for pid %d\n", pid);
 404
 405         map->map[i].comm = comm;
 406 }
 407
 408 void thread_map__read_comms(struct thread_map *threads)
 409 {
 410         int i;
 411
 412         for (i = 0; i < threads->nr; ++i)
 413                 comm_init(threads, i);
 414 }
 415
 416 static void thread_map__copy_event(struct thread_map *threads,
 417                                    struct thread_map_event *event)
 418 {
 419         unsigned i;
 420
 421         threads->nr = (int) event->nr;
 422
 423         for (i = 0; i < event->nr; i++) {
 424                 thread_map__set_pid(threads, i, (pid_t) event->entries[i].pid);
 425                 threads->map[i].comm = strndup(event->entries[i].comm, 16);
 426         }
 427
 428         refcount_set(&threads->refcnt, 1);
 429 }
 430
 431 struct thread_map *thread_map__new_event(struct thread_map_event *event)
 432 {
 433         struct thread_map *threads;
 434
 435         threads = thread_map__alloc(event->nr);
 436         if (threads)
 437                 thread_map__copy_event(threads, event);
 438
 439         return threads;
 440 }
 441
 442 bool thread_map__has(struct thread_map *threads, pid_t pid)
 443 {
 444         int i;
 445
 446         for (i = 0; i < threads->nr; ++i) {
 447                 if (threads->map[i].pid == pid)
 448                         return true;
 449         }
 450
 451         return false;
 452 }
 453
 454 int thread_map__remove(struct thread_map *threads, int idx)
 455 {
 456         int i;
 457
 458         if (threads->nr < 1)
 459                 return -EINVAL;
 460
 461         if (idx >= threads->nr)
 462                 return -EINVAL;
 463
 464         /*
 465          * Free the 'idx' item and shift the rest up.
 466          */
 467         free(threads->map[idx].comm);
 468
 469         for (i = idx; i < threads->nr - 1; i++)
 470                 threads->map[i] = threads->map[i + 1];
 471
 472         threads->nr--;
 473         return 0;
 474 }